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-rw-r--r--vppinfra/tools/elftool.c459
1 files changed, 459 insertions, 0 deletions
diff --git a/vppinfra/tools/elftool.c b/vppinfra/tools/elftool.c
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+++ b/vppinfra/tools/elftool.c
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+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+ Copyright (c) 2008 Eliot Dresselhaus
+
+ Permission is hereby granted, free of charge, to any person obtaining
+ a copy of this software and associated documentation files (the
+ "Software"), to deal in the Software without restriction, including
+ without limitation the rights to use, copy, modify, merge, publish,
+ distribute, sublicense, and/or sell copies of the Software, and to
+ permit persons to whom the Software is furnished to do so, subject to
+ the following conditions:
+
+ The above copyright notice and this permission notice shall be
+ included in all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include <vppinfra/elf.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#ifndef CLIB_UNIX
+#error "unix only"
+#endif
+
+typedef struct {
+ elf_main_t elf_main;
+ char * input_file;
+ char * output_file;
+ char * set_interpreter;
+ char * set_rpath;
+ int unset_rpath;
+ int verbose;
+ int quiet;
+ int allow_elf_shared;
+ /* for use in the optimized / simplified case */
+ u64 file_size;
+ u64 interpreter_offset;
+ u64 rpath_offset;
+} elf_tool_main_t;
+
+static clib_error_t * elf_set_interpreter (elf_main_t * em,
+ elf_tool_main_t * tm)
+{
+ elf_segment_t * g;
+ elf_section_t * s;
+ clib_error_t * error;
+ char * interp = tm->set_interpreter;
+
+ switch (em->first_header.file_type)
+ {
+ case ELF_EXEC:
+ break;
+
+ case ELF_SHARED:
+ if (tm->allow_elf_shared)
+ break;
+ /* Note flowthrough */
+ default:
+ return clib_error_return (0, "unacceptable file_type");
+ }
+
+ vec_foreach (g, em->segments)
+ {
+ if (g->header.type == ELF_SEGMENT_INTERP)
+ break;
+ }
+
+ if (g >= vec_end (em->segments))
+ return clib_error_return (0, "interpreter not found");
+
+ if (g->header.memory_size < 1 + strlen (interp))
+ return clib_error_return (0, "given interpreter does not fit; must be less than %d bytes (`%s' given)",
+ g->header.memory_size, interp);
+
+ error = elf_get_section_by_start_address (em, g->header.virtual_address, &s);
+ if (error)
+ return error;
+
+ /* Put in new null terminated string. */
+ memset (s->contents, 0, vec_len (s->contents));
+ memcpy (s->contents, interp, strlen (interp));
+
+ return 0;
+}
+
+static void
+delete_rpath_for_section (elf_main_t * em, elf_section_t * s)
+{
+ elf64_dynamic_entry_t * e;
+ elf64_dynamic_entry_t * new_es = 0;
+
+ vec_foreach (e, em->dynamic_entries)
+ {
+ switch (e->type)
+ {
+ case ELF_DYNAMIC_ENTRY_RPATH:
+ case ELF_DYNAMIC_ENTRY_RUN_PATH:
+ break;
+
+ default:
+ vec_add1 (new_es, e[0]);
+ break;
+ }
+ }
+
+ /* Pad so as to keep section size constant. */
+ {
+ elf64_dynamic_entry_t e_end;
+ e_end.type = ELF_DYNAMIC_ENTRY_END;
+ e_end.data = 0;
+ while (vec_len (new_es) < vec_len (em->dynamic_entries))
+ vec_add1 (new_es, e_end);
+ }
+
+ vec_free (em->dynamic_entries);
+ em->dynamic_entries = new_es;
+
+ elf_set_dynamic_entries (em);
+}
+
+static void delete_rpath (elf_main_t * em)
+{
+ elf_section_t * s;
+
+ vec_foreach (s, em->sections)
+ {
+ switch (s->header.type)
+ {
+ case ELF_SECTION_DYNAMIC:
+ delete_rpath_for_section (em, s);
+ break;
+
+ default:
+ break;
+ }
+ }
+}
+
+static clib_error_t *
+set_rpath_for_section (elf_main_t * em, elf_section_t * s, char * new_rpath)
+{
+ elf64_dynamic_entry_t * e;
+ char * old_rpath;
+ int old_len, new_len = strlen (new_rpath);
+ u8 * new_string_table = vec_dup (em->dynamic_string_table);
+
+ vec_foreach (e, em->dynamic_entries)
+ {
+ switch (e->type)
+ {
+ case ELF_DYNAMIC_ENTRY_RPATH:
+ case ELF_DYNAMIC_ENTRY_RUN_PATH:
+ old_rpath = (char *) new_string_table + e->data;
+ old_len = strlen (old_rpath);
+ if (old_len < new_len)
+ return clib_error_return (0, "rpath of `%s' does not fit (old rpath `%s')",
+ new_rpath, old_rpath);
+ strcpy (old_rpath, new_rpath);
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ elf_set_section_contents (em, em->dynamic_string_table_section_index,
+ new_string_table,
+ vec_bytes (new_string_table));
+
+ return 0;
+}
+
+static clib_error_t *
+set_rpath (elf_main_t * em, char * rpath)
+{
+ clib_error_t * error = 0;
+ elf_section_t * s;
+
+ vec_foreach (s, em->sections)
+ {
+ switch (s->header.type)
+ {
+ case ELF_SECTION_DYNAMIC:
+ error = set_rpath_for_section (em, s, rpath);
+ if (error)
+ return error;
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ return error;
+}
+
+static clib_error_t *
+set_interpreter_rpath (elf_tool_main_t * tm)
+{
+ int ifd = -1, ofd = -1;
+ struct stat fd_stat;
+ u8 *idp = 0; /* warning be gone */
+ u64 mmap_length = 0, i;
+ u32 run_length;
+ u8 in_run;
+ u64 offset0 = 0, offset1 = 0;
+ clib_error_t * error;
+ int fix_in_place = 0;
+
+ if (!strcmp (tm->input_file, tm->output_file))
+ fix_in_place = 1;
+
+ ifd = open (tm->input_file, O_RDWR);
+ if (ifd < 0)
+ {
+ error = clib_error_return_unix (0, "open `%s'", tm->input_file);
+ goto done;
+ }
+
+ if (fstat (ifd, &fd_stat) < 0)
+ {
+ error = clib_error_return_unix (0, "fstat `%s'", tm->input_file);
+ goto done;
+ }
+
+ if (!(fd_stat.st_mode & S_IFREG))
+ {
+ error = clib_error_return (0, "%s is not a regular file", tm->input_file);
+ goto done;
+ }
+
+ mmap_length = fd_stat.st_size;
+ if (mmap_length < 4)
+ {
+ error = clib_error_return (0, "%s too short", tm->input_file);
+ goto done;
+ }
+
+ /* COW-mapping, since we intend to write the fixups */
+ if (fix_in_place)
+ idp = mmap (0, mmap_length, PROT_READ | PROT_WRITE, MAP_SHARED,
+ ifd, /* offset */ 0);
+ else
+ idp = mmap (0, mmap_length, PROT_READ | PROT_WRITE, MAP_PRIVATE,
+ ifd, /* offset */ 0);
+ if (~pointer_to_uword (idp) == 0)
+ {
+ mmap_length = 0;
+ error = clib_error_return_unix (0, "mmap `%s'", tm->input_file);
+ goto done;
+ }
+
+ if (idp[0] != 0x7f || idp[1] != 'E' || idp[2] != 'L' || idp[3] != 'F')
+ {
+ error = clib_error_return (0, "not an ELF file '%s'", tm->input_file);
+ goto done;
+ }
+
+ in_run = 0;
+ run_length = 0;
+
+ for (i = 0; i < mmap_length; i++)
+ {
+ if (idp[i] == '/')
+ {
+ if (in_run)
+ run_length++;
+ else
+ {
+ in_run = 1;
+ run_length = 1;
+ }
+ }
+ else
+ {
+ if (in_run && run_length >= 16)
+ {
+ if (offset0 == 0)
+ offset0 = (i - run_length);
+ else if (offset1 == 0)
+ {
+ offset1 = (i - run_length);
+ goto found_both;
+ }
+ }
+ in_run = 0;
+ run_length = 0;
+ }
+ }
+
+ if (offset0 == 0)
+ {
+ error = clib_error_return (0, "no fixup markers in %s",
+ tm->input_file);
+ goto done;
+ }
+
+ found_both:
+ if (0)
+ clib_warning ("offset0 %lld (0x%llx), offset1 %lld (0x%llx)",
+ offset0, offset0, offset1, offset1);
+
+ /* Executable file case */
+ if (offset0 && offset1)
+ {
+ tm->interpreter_offset = offset0;
+ tm->rpath_offset = offset1;
+ }
+ else /* shared library case */
+ {
+ tm->interpreter_offset = 0;
+ tm->rpath_offset = offset0;
+ }
+
+ if (tm->interpreter_offset)
+ memcpy (&idp[tm->interpreter_offset], tm->set_interpreter,
+ strlen (tm->set_interpreter)+1);
+
+ if (tm->rpath_offset)
+ memcpy (&idp[tm->rpath_offset], tm->set_rpath,
+ strlen (tm->set_rpath)+1);
+
+ /* Write the output file... */
+ if (fix_in_place == 0)
+ {
+ ofd = open (tm->output_file, O_RDWR | O_CREAT | O_TRUNC, 0644);
+ if (ofd < 0)
+ {
+ error = clib_error_return_unix (0, "create `%s'", tm->output_file);
+ goto done;
+ }
+
+ if (write (ofd, idp, mmap_length) != mmap_length)
+ error = clib_error_return_unix (0, "write `%s'", tm->output_file);
+ }
+
+ done:
+ if (mmap_length > 0)
+ munmap (idp, mmap_length);
+ close (ifd);
+ close (ofd);
+ return error;
+}
+
+
+int main (int argc, char * argv[])
+{
+ elf_tool_main_t _tm, * tm = &_tm;
+ elf_main_t * em = &tm->elf_main;
+ unformat_input_t i;
+ clib_error_t * error = 0;
+
+ memset (tm, 0, sizeof (tm[0]));
+ unformat_init_command_line (&i, argv);
+
+ while (unformat_check_input (&i) != UNFORMAT_END_OF_INPUT)
+ {
+ if (unformat (&i, "in %s", &tm->input_file))
+ ;
+ else if (unformat (&i, "out %s", &tm->output_file))
+ ;
+ else if (unformat (&i, "set-interpreter %s", &tm->set_interpreter))
+ ;
+ else if (unformat (&i, "set-rpath %s", &tm->set_rpath))
+ ;
+ else if (unformat (&i, "unset-rpath"))
+ tm->unset_rpath = 1;
+ else if (unformat (&i, "verbose"))
+ tm->verbose = ~0;
+ else if (unformat (&i, "verbose-symbols"))
+ tm->verbose |= FORMAT_ELF_MAIN_SYMBOLS;
+ else if (unformat (&i, "verbose-relocations"))
+ tm->verbose |= FORMAT_ELF_MAIN_RELOCATIONS;
+ else if (unformat (&i, "verbose-dynamic"))
+ tm->verbose |= FORMAT_ELF_MAIN_DYNAMIC;
+ else if (unformat (&i, "quiet"))
+ tm->quiet = 1;
+ else if (unformat (&i, "allow-elf-shared"))
+ tm->allow_elf_shared = 1;
+ else
+ {
+ error = unformat_parse_error (&i);
+ goto done;
+ }
+ }
+
+ if (! tm->input_file)
+ clib_error ("no input file");
+
+ /* Do the typical case a stone-simple way... */
+ if (tm->quiet && tm->set_interpreter && tm->set_rpath && tm->output_file)
+ {
+ error = set_interpreter_rpath (tm);
+ goto done;
+ }
+
+ error = elf_read_file (em, tm->input_file);
+
+ if (error)
+ goto done;
+
+ if (tm->verbose)
+ fformat (stdout, "%U", format_elf_main, em, tm->verbose);
+
+ if (tm->set_interpreter)
+ {
+ error = elf_set_interpreter (em, tm);
+ if (error)
+ goto done;
+ }
+
+ if (tm->set_rpath)
+ {
+ error = set_rpath (em, tm->set_rpath);
+ if (error)
+ goto done;
+ }
+
+ if (tm->unset_rpath)
+ delete_rpath (em);
+
+ if (tm->output_file)
+ error = elf_write_file (em, tm->output_file);
+
+ elf_main_free (em);
+
+ done:
+ if (error)
+ {
+ if (tm->quiet == 0)
+ clib_error_report (error);
+ return 1;
+ }
+ else
+ return 0;
+}